Pendulums Class - Love

pendulumsclass.lua

-- http://i.imgur.com/0X0LTRs.gif by /r/davebees

-- recreated (to some degree) by @josefnpat

-- pendulumsclass.lua

local pendulums = {}

function pendulums.new(x,y,r,lcount)
  local self = {}

  -- Overrides
  self._x = x or love.graphics.getWidth()/2
  self._y = y or love.graphics.getHeight()/8
  self._r = r or love.graphics.getHeight()*6/8
  self._lcount=lcount or 10

  -- Inits
  self._dt = 0

  -- Methods
  self.draw = pendulums.draw
  self.update = pendulums.update
  self.drawpendulum = pendulums.drawpendulum

  return self
end

function pendulums:draw()
  for i = 1,self._lcount do
    self:drawpendulum( (self._lcount - i + 1)/2, i/self._lcount*self._r )
  end
end

function pendulums:update(dt)
  self._dt = self._dt + dt  
end

function pendulums:drawpendulum(i,r)
  local angle = math.sin(self._dt*i) + math.pi/2
  local xt = self._x + r*math.cos(angle)
  local yt = self._y + r*math.sin(angle)
  love.graphics.line(self._x,self._y,xt,yt)
  love.graphics.circle("fill",xt,yt,6)
end

return pendulums